Even if it were possible to evaluate all current alternatives, we lack knowledge of the future and therefore can't reliably include important factors such as ability to hire into the team.
I agree, and think that the culture around a programming language is one of the most important attributes, so we should not be afraid to talk about human factors like cultural fit. Your choice of programming language is usually limited to a short list of the ones that have the tools and libraries to support what you are doing, but IMO it's perfectly reasonable to choose a particular language because you and your team like the culture. If you decide to use a programming language in production, you might have to live with it for a long time.
Not perfectly because "best" is subjective. My advice is to let the problem and goals help you dictate (yes, even on hobby projects and even if one of the goals is trying said language). In fact, if you are a hobbyist evaluating languages, you should try them all out with reasonable projects where you can instead of write a post saying how you are moving from a single one to another single one.
I think that's an objectively false statement.
There are many objective metrics by which a programming language may be evaluated. Conciseness, clarity, suitability for realtime applications, and efficiency come to mind.
"It is even possible to "use the best language for the problem"?"
It's certainly possible to use a suitable language for the problem. Some problems are more forgiving than others, of course...
I will say that the idea of a "general purpose" programming language, suitable for most tasks, is a good one. The current multitude of languages, while fun and good for exploring new ideas, is taking a lot of brainpower away from actually producing working systems. Also, I'll claim that there's no reason that most programs shouldn't be written in an efficient language, and in fact there may be a push for that in the name of datacenter efficiency.
It's sad that the most written programming language today is Javascript.